KR20010045087A - Inorganic chemical treatment of industrial wastewater - Google Patents

Abstract

PURPOSE: Disclosed is a method for treating wastewater using inorganic feed for improving treatment efficiency. Above method comprises the steps of (a) injecting inorganic feed for improving removal efficiency of BOD (Biological Oxygen Demand) and COD (Chemical Oxygen Demand); (b) irradiating supersonic wave for removing non-biodegradable organic compounds; and (c) injecting ozone thereinto for deodorizing and decolorizing. CONSTITUTION: The inorganic feed is made by follow steps: (a) mixing ammonia gas with 0.1 M sulfuric acid solution; (b) electrolysis thereof for getting (NH4)2S2O8; (c) mixing of (NH)2S2O8, NaOH, and Al2O3 in a molar ratio of 1:2:1 for 24 hours; (d) drying it at 110 deg.C; (e) calcining at 400 deg.C with air blow; and (f) cooling it for getting precipitate.

Description

Inorganic chemical treatment of industrial wastewater

The present invention relates to a method for treating sewage and industrial wastewater, and more particularly, in the recycling of sewage and industrial wastewater, by using a ozone generator and an ultrasonic wave, by adding a specific inorganic sample, BOD and COD removal rates are increased in a short time. The present invention relates to a method for treating a large amount of wastewater.

As the amount of wastewater discharged from various industries increases, the composition is also diversified, and environmental risks to humans and ecosystems caused by the release of harmful substances are being raised seriously.

In addition, as the components of the wastewater are diversified, the conventional treatment technology tends not to be easily decomposed or removed even in wastewater treatment. Therefore, there is an urgent need for the development of new technologies that can effectively remove these components from toxic wastewater. have.

The existing Fenton method or final filtration system among sewage and wastewater treatment methods and facilities causes anaerobic decomposition inside the filtration tank due to organic matter and micro suspended solids caused by the lack of dissolved oxygen after biological treatment, causing odor to the treated water. The clogging of activated carbon causes the filtration and treatment efficiency to drop dramatically, making it difficult to continue using. In addition, due to unstable biological treatment or negligence of management, the effluent has high chromaticity or organic matter concentration, which lowers the filtration performance, and the COD and BOD treatment efficiency is insufficient.

An object of the present invention is to solve the problems as described above, and to provide a method for treating sewage and industrial wastewater that can be treated with high selectivity under normal temperature and atmospheric pressure while having an excellent industrial wastewater treatment function.

It is also an object of the present invention to provide a new and efficient wastewater treatment method capable of treating a large amount of wastewater in a short time.

In addition, an object of the present invention is to provide a method for efficiently treating a hardly decomposable organic material that is not easily treated with a conventional Fenton method for a short time.

The treatment method of sewage and industrial wastewater of the present invention for achieving the above object comprises the steps of increasing the removal efficiency of BOD and COD by adding an inorganic sample to the wastewater containing hardly decomposable organic compounds; Decomposing and removing the organic compound using ultrasonic waves to obtain a filtrate; Ozone treatment of the filtrate is characterized by consisting of an oxidation step of deodorizing color and.

In the present invention, a particular inorganic sample was prepared for industrial wastewater treatment, and the manufacturing mechanism of the inorganic sample was as follows.

Ammonia sulfate is obtained by electrolysis using a reactant of ammonia gas and 0.1M sulfuric acid solution at room temperature and atmospheric pressure, and sulfuric acid solution is repeated to the product to obtain diammonium persulfate. At this time, the yield is 95 and precipitates on cooling.

The product thus obtained selectively adsorbs and decomposes wastewater containing phenol to produce carbon dioxide and water.

The inorganic sample obtained according to the present invention is a composite oxide showing excellent selectivity to organic materials, and has excellent stability and wide surface area compared to other wastewater treatment agents.

Looking at the manufacturing method of the inorganic sample of the wastewater treatment agent of the present invention in more detail;

A typical method for producing a wastewater treatment agent and application of wastewater treatment reaction is to obtain ammonium peroxide as a current is passed through an electrode composed of platinum and graphite rods while blowing ammonia gas into 0.1M sulfuric acid solution in a reaction electrolyzer. Alumina was used to metathesize this again or use the product obtained through the electrolytic cell in water treatment, and sodium was dissolved in sodium hydroxide and iron oxide in a 0.1 M ammonium peroxide solution (NH ₄ ) ₂ S ₂ O ₈ : NaOH: Al ₂ O _It melt | dissolved so that it may become ₃ = 1: 2: 1, and it stirred for 24 hours, and drying was performed by blowing air in the high temperature furnace which maintained at 400 degreeC in the oven maintained at 110 degreeC.

An example of the preparation process of the inorganic sample obtained according to the present invention is shown in Scheme 1 below.

Electric energy

2NH ₃ + 2H ₂ SO ₄ -----------> (NH ₄ ) ₂ S ₂ O ₈ + H ₂

(NH ₄ ) ₂ S ₂ O ₈ + ₂ NaOH + Al ₂ O ₃ ------------> Na ₂ S ₂ Al ₂ O ₁₀ (H ₂ O) + 2NH ₄ OH

Using these reactants, an inorganic sample according to the present invention is obtained in an electrolytic cell using a diaphragm or without a diaphragm. The process voltage is 8 to 12 V, a current is 4 to 15 V, and a current density is 0.1 to 0.15 A. / Cm 2. The overall yield is about 90 when compared with the power used, alkali persulfate salts and the like can be obtained by metathesis, pure inorganic samples are precipitated upon cooling and recycled to the electrolysis bath by adding the reactants to the mother liquor. Concentration of the resultant flotation results in an inorganic sample used as wastewater treatment agent in the present invention.

The reaction proceeds in a reactor called a saturator, where the fine crystals are allowed to stay long enough to grow to a reasonable size. In the electrochemical process, an aqueous solution of sulfuric acid, sulfuric acid, and sulfuric ammonium is electrochemically oxidized at the anode to produce disulfide peroxide or ammonium persulfate, thereby preparing an inorganic sample. Diammonium persulfate is obtained by electrolyzing ammonium sulfate and sulfuric acid solution, and the inorganic sample in which the product obtained by electrolysis of diammonium persulfate and sodium hydroxide by electrolysis or metathesis reaction is used as wastewater treatment agent in the present invention. Becomes

In this case, the mass spectrometry of the element is analyzed using an atomic absorption spectrometer.

In addition to the compounds described above, the inorganic compounds include oxygen ions, permanganate ions, hypochlorite ions, chlorine ions, dioxide ions, bichromate ions, sulfite ions, persulfate ions, phosphate ions, diphosphate ions, nitrate ions, and sulfuric acid. Ions, bromine, fluorine, iodine, boric acid, acetate, formic acid, terephthalate, maleic acid, urea, adipic acid, etc., and the cation is composed of lithium, calcium, iron, magnesium, sodium And all compounds which are aluminum, nickel, zinc, tin or manganese.

In the method for treating industrial wastewater using the inorganic sample thus obtained, first, the inorganic sample is added to the wastewater containing hardly decomposable organic compounds under normal temperature and atmospheric pressure to increase the removal efficiency of BOD and COD.

The content of the added inorganic sample may vary depending on the COD and BOD of the industrial wastewater. For example, the amount of the inorganic sample is preferably 25 ppm for 5,000 ml of the industrial wastewater of 1,300 ppm COD.

Ultrasonic irradiation then decomposes and removes the organic compounds contained in the wastewater.

When the ultrasonic wave is irradiated with an aqueous solution, the organic compound is decomposed and removed due to the cavitation that occurs when the ultrasonic wave is irradiated with an aqueous solution. The area where the organic compound is removed is placed in the cavity, near the wall of the cavity, and in the aqueous solution. It can be divided into three areas such as high temperature part.

Looking at the response patterns in these three regions; First of all, the temperature and pressure inside the cavitation bubble are about 5,000 ° K and over 500 atm due to the very high energy generated during the cavitation process. Therefore, organic compounds are directly pyrolyzed by high temperature heat in these two regions. The high-temperature, high-pressure energy released when the cavitation bubble bursts causes some water molecules to decompose into hydroxyl radicals and hydrogen radicals, and these radicals combine with organic materials to break down into new materials of lower molecular weight.

Ultrasonic waves cause the shock wave generated by the bursting of bubbles to become hundreds of atmospheres, and these high-pressure shock waves cause the decomposition of constituents near the bubbles. At a given pressure and temperature, fluctuations depending on the temperature of the water quickly create or break up the filled microscopic-vapor cavitation. These fluctuations increase the action of ozone, an inorganic sample and a post-process.

The inorganic sample according to the present invention is a non-volatile scavenger that can effectively reduce BOD and COD and does not affect the production of hydrogen peroxide, and the efficiency is increased by hydroxyl radicals and hydrogen radicals generated by dissociation of water in the ultrasonic reaction of aqueous solution. Is increased.

Ultrasonic irradiation of a suspension of organic chemicals decomposes the substance, producing a variety of decomposition products. In particular, in aqueous solution, hardly decomposable organic compounds and water molecules dissociate to form intermediate products having high reactivity, and may be directly reacted by oxidation or reduction of highly reactive water with intermediate decomposition products. Branch decomposition products are produced. Homogeneous sonocatalysis studies in the chemistry of oxidizing alkenes with oxygen show that ultrasound is used as a homogeneous catalyst because ultrasound can induce ligand dissociation of chemicals.

On the other hand, when irradiated with ultrasonic waves in the water dissolved oxygen, a considerable amount of peroxide is produced without breaking O-O bonds.

In the present invention, for the ultrasonic treatment, an electron beam, an electromagnetic wave, an ultraviolet ray, a pulse corona discharge plasma, or the like can be used.

As such, ozone treatment is performed on the filtrate from which the organic compound is decomposed and removed by adding an inorganic sample and sonicating. In general, the cause of the color of the waste water is that a specific wavelength of natural light is absorbed and scattered in the waste water. In the present invention, when the substance to be colored is suspended or dissolved in colloidal particles in an aqueous solution, the decoloring method in the present invention is a chemical method of oxidizing and removing the chemical structure of the dissolved colored substance with an oxidizing agent.

The role of the oxidant in the present invention is ozone, and together with ozone, the inorganic sample has a strong oxidizing power to oxidize dissolved organic substances in water and decolorize and deodorize to recycle water.

As an example, the oxidation reaction of the halogen organic material in the aqueous solution, for example, trichloroethane contained in the aqueous solution is left through the unsaturated hydrocarbon chloride, unsaturated hydrocarbon, carbon dioxide and water.

Adding inorganic samples to sewage and industrial wastewater as described above and treating them for 30 minutes using ultrasonic wave and ozone generator will decompose and remove hardly decomposable organic substances, decolorize and sterilize them, and reduce BOD to be recycled into water. Is done.

The standard value for the treatment of ultrasonic waves and ozone is 24,000 rpm of ultrasonic water per 5,000 ml of waste water and the amount of ozone is 2.0 g / hr.

In the embodiment of the present invention, the method for treating leather wastewater was mentioned, and the following experiment was conducted to test the effect of leather wastewater treatment.

Into the test tank (10,000 ml), take 5,000 ml of secondary treatment water from the leather processing plant with daily discharge of 15 tons, and then put the inorganic sample into the ultra high-frequency generator model of Ultra Taurax T25B from IKA Labortechnic staufen, which is a piezoelectric transducer and attached to the bottom of the reactor. Titanium probe (28 kHz, 700 W) was used. Then, a voltage was applied to the ultrasonic waves for 40 minutes to treat organic materials.

On the other hand, by using the ozone generator in combination with the inorganic sample, the organic material was treated by treating the voltage for 40 minutes.

Finally, by applying the ultrasonic wave to the ozone generating device in combination with the ultrasonic wave in the wastewater treatment method of the present invention and treated for 40 minutes each to treat the organic material.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited by the Examples.

Comparative Examples 1 to 5

These examples are the result of treating Na ₂ S ₂ Al ₂ O ₁₀ with an inorganic sample to the leather wastewater and treating it for 40 minutes with ultrasound. Each example differs only in that the content of the inorganic sample added is changed as shown in Table 1 below.

As a control, the dissolved oxygen, biological oxygen demand, chemical oxygen demand, color, and odor of the treated wastewater were measured by using only the ultrasonic wave without the inorganic sample. Table 1 shows.

Inorganic Sample Injection (ppm) Measure Removal rate () Dissolved oxygen BOD COD Chromaticity stink Comparative Example One 20 57 52 59 70 76 2 25 64 55 68 79 80 3 30 64 55 68 78 80 4 35 64 55 68 79 79 5 40 64 55 68 78 80 Control - 19 21 15 8 10

From the results of Table 1, the addition of inorganic samples and ultrasonic treatment, as well as color and odor treatment, as well as DO, BOD, COD treatment efficiency was more than 60, it can be seen that the ideal results when the injection amount of inorganic samples 25ppm have. However, it can be seen that when only ultrasonic waves are treated without adding an inorganic sample, the DO, BOD, and COD treatment efficiency as well as chromaticity and odor are low.

Comparative Examples 6 to 10

These examples are the result of treatment of Na ₂ S ₂ Al ₂ O ₁₀ with inorganic samples to the leather wastewater and treatment of voltage for 40 minutes using an ozone generator. Each example differs only in that the content of the inorganic sample added is changed as shown in Table 2 below.

As a control, the dissolved oxygen, biological oxygen demand, chemical oxygen demand, color and odor of the treated wastewater were measured using the ozone treatment without the addition of inorganic samples. It is shown in Table 2 below.

Inorganic Sample Injection (ppm) Measure Removal rate () Dissolved oxygen BOD COD Chromaticity stink Comparative Example 6 20 62 47 49 60 66 7 25 65 58 53 69 60 8 30 65 58 53 68 67 9 35 65 58 53 69 69 10 40 65 57 53 68 69 Control - 19 12 10 21 24

From the results of Table 2, when the inorganic sample was added and ozone treatment, as well as color and odor treatment, the DO, BOD, COD treatment efficiency was 45 or more, and when the amount of the inorganic sample was 25ppm, it can be seen that the ideal result was obtained. . However, in the case of ozone treatment without the addition of inorganic samples, it can be seen that the DO, BOD, and COD treatment efficiencies as well as chromaticity and odor are low.

Examples 1-5 and Comparative Examples 1-5

This embodiment is the result of treating Na ₂ S ₂ Al ₂ O ₁₀ with an inorganic sample in leather wastewater and applying an ozone generating device as well as ultrasonic waves to apply voltage and treating each organic material for 40 minutes each. . Each example differs only in that the content of the inorganic sample added is changed as shown in Table 3 below.

As a comparative example, the results of each treatment of the leather wastewater were treated with a mixed solution of hydrogen peroxide and iron (II) sulfate according to the conventional Fenton method, and the amount of dissolved oxygen, biological oxygen demand, Chemical oxygen demand, color and odor were measured and the results are shown in Table 3 below.

Inorganic Sample Injection (ppm) Measure Removal rate () Dissolved oxygen BOD COD Chromaticity stink Example One 20 87 72 79 90 96 2 25 94 83 88 99 100 3 30 94 81 88 98 100 4 35 94 80 88 99 99 5 40 94 75 88 98 100 Comparative example One 20 23 21 15 8 10 2 25 25 23 17 8 10 3 30 29 26 19 12 13 4 35 32 30 28 17 14 5 40 41 36 45 22 18

From the results of Table 3, when ultrasonic and ozone were treated after the addition of the inorganic sample, the DO, BOD, COD treatment efficiency was higher as well as the color and odor treatment compared to those of Tables 1 and 2, When the injection amount is 25ppm it can be seen that the ideal results. In comparison with the Fenton method using a conventional strong oxidizing agent, it can be seen that the DO, BOD, COD treatment efficiency is high, including color and odor.

Experimental Example

Meanwhile, 5,000 ml of secondary treated water from a leather processing plant with 15 tons of daily emissions was put into 10,000 ml of test sample, 25 ppm of inorganic sample was dosed, and ultrasonic and ozone treatment times were performed for 10, 20, 30 and 40 minutes, respectively. The results are shown in Table 4. At this time, as a control, as shown in the case of using the Fenton reagent hydrogen peroxide and iron (II) sulfate 25ppm as in the comparative example for 10, 20, 30 and 40 minutes respectively.

Processing time (minutes) Measure Removal rate () Dissolved oxygen BOD COD Chromaticity stink Example One 10 68 63 57 25 80 2 20 73 70 69 80 82 3 30 94 81 88 100 100 4 40 94 79 88 100 100 Comparative example One 10 12 16 11 5 8 2 20 21 23 15 5 9 3 30 40 32 19 10 13 4 40 41 35 27 19 18

From the results of Table 4, after quantitatively administering the inorganic sample as in the present invention, the results of the examination of the results of the ultrasonic and ozone treatment time were 30 minutes. On the other hand, in the case of the comparative example, the treatment efficiency is improved as time passes, but it can be seen that the treatment efficiency is significantly lower than that of the present invention.

As described in detail above, when the specific inorganic sample prepared according to the present invention is added, and the wastewater is treated in parallel with the ultrasonic and ozone treatment, a treatment method using a conventional strong oxidizing agent or only ultrasonic or ozone is used. Compared to the case of treatment, the treatment efficiency is greatly improved and the treatment time can be shortened, and in particular, the efficiency of the wastewater treatment containing hardly decomposable organic compounds such as phenol is excellent.

Claims (7)

Increasing the removal efficiency of BOD and COD by adding an inorganic sample (content: 25 ppm per 5,000 ml of waste water having a COD of 1300 ppm) to the wastewater containing hardly decomposable organic compounds; Generating an filtrate from which the hardly decomposable organic compound is decomposed and removed by generating ultrasonic waves in the treated material; And A method of treating sewage and industrial wastewater comprising an oxidation step of deodorizing the filtrate by ozone treatment of the filtrate. The method of claim 1, A method for treating sewage and industrial wastewater, wherein the inorganic sample is omitted and the ultrasonic wave and ozone are used together. The method of claim 1, The method for treating sewage and industrial wastewater, wherein the ozone is omitted and the inorganic sample and the ultrasonic wave are used together. The method of claim 1, The inorganic sample includes oxygen ions, permanganate ions, hypochlorite ions, chlorine ions, dioxide ions, bichromate ions, sulfite ions, persulfate ions, phosphate ions, diphosphate ions, nitrate ions, sulfate ions, bromine ions, and fluorine ions. , Anion components selected from iodine ion, borate ion, acetate ion, formate ion, terephthalate ion, maleic acid ion, urea ion and adipic acid ion, and lithium, calcium, iron, magnesium, sodium, aluminum, nickel, zinc, A process for treating sewage and industrial wastewater, characterized by using a compound consisting of a cation component selected from tin or manganese compounds. The method according to claim 1 or 4, The inorganic sample is a method for treating sewage and industrial wastewater, characterized in that a compound obtained by electrolyzing ammonia, sulfuric acid, sodium hydroxide and alumina is used. The method of claim 1, The hardly decomposable organic compound is a phenol or a halogen compound, characterized in that the treatment of industrial wastewater. The method of claim 1, The ultrasonic wave is generated using an electron beam, electromagnetic waves, ultraviolet rays and pulsed corona discharge plasma, characterized in that the treatment method for sewage and industrial wastewater.